• Transactions of the Society of Information Storage Systems
• /
• v.2 no.4
• /
• pp.214-218
• /
• 2006

The focus and tracking servo system has been designed and proposed for the holographic memory of one dimensional spatial light modulator(SLM). The general servo method of conventional ODD system was based and modified for new holographic memory. The pre-grooved disc pattern and special dichroic coating were also included for new design in this research and the final separated optics are expected to be applied to the future general holographic memory as well as the one dimensional SLM holographic memory.

• Proceedings of the Optical Society of Korea Conference
• /
• 1989.02a
• /
• pp.99-102
• /
• 1989

Optical implementation of adaptive quadratic associative memory for two-dimensional patterns is described by using holographic lenslet arrays and spatial light modulators. Basic experimental results demonstrating its feasibility are reported.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.9
• /
• pp.1102-1107
• /
• 1988

We describe a volume holographic associative memory using photorefractive material and conventional planar mirror. Multiple hologram is generated with two angular multiplexed writing beams and Fourier transformed object beam in Ba Ti O3 crystal at 0.6328 um. Complete image can be recalled successfully by partial input of the original stored image without any additional thresholding and optical feedback process. It is proved that our system is useful for optical implementation of real-time associative memory and location addressable memory.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2002.11a
• /
• pp.243-246
• /
• 2002

We proposed a new spatio-angularly multiplexed holographic memory system using moving windows and double-focusing lens, which can eleminate crosstalk due to two neighboring moving windows(MW) in the vertical direction of the conventional MW holographic memory system and demonstated its feasibility through optical experiments.

• Proceedings of the Optical Society of Korea Conference
• /
• 1991.07a
• /
• pp.33-39
• /
• 1991

We have developed a new holographic associative memory(HAN) based on an adaptive learning which uses learning pattern method (LPM). The LPM utilizes the simple optical implementation of outer-product learning, performance of adapitive learning. simulation are represented.

• Proceedings of the KAIS Fall Conference
• /
• 2000.10a
• /
• pp.214-217
• /
• 2000

We suggested a new non-mechanical angular multiplexed holographic memory system using a moving window. The feasibility of the proposed method was demonstrated through optical experiments and its crosstalk noise analysis were also presented

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.29 no.6
• /
• pp.327-331
• /
• 2016

Resistive random access memory (ReRAM) of metallic conduction channel mechanism is based on the electrochemical control of metal in solid electrolyte thin film. Amorphous chalcogenide materials have the solid electrolyte characteristic and optical reactivity at the same time. The optical reactivity has been used to improve the memory switching characteristics of the amorphous $As_2Se_3$-based ReRAM. This study focuses on the formation of holographic lattices patterns in the amorphous $As_2Se_3$ thin film for straight conductive channel. The optical parameters of amorphous $As_2Se_3$ thin film which is a refractive index and extinction coefficient was taken by n&k thin film analyzer. He-Cd laser (wavelength: 325 nm) was selected based on these basic optical parameters. The straighten conduction channel was formed by holographic lithography method using He-Cd laser.$ Ag^+$ ions that photo-diffused periodically by holographic lithography method will be the role of straight channel patterns. The fabricated ReRAM operated more less voltage and indicated better reliability.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.41 no.2
• /
• pp.89-98
• /
• 2004

In this paper, we implement a digital holographic security card system that combines digital holographic memory using random phase encoded reference beams with electrical biometrics. Digitally encoded data including a document, a picture of face, and a fingerprint are recorded by multiplexing of holographic memory. A random phase mask encoding reference beams are used as a decoded key to protect illegal counterfeit. As a result, we can achieve a raw BER of 3.6${\times}$10-4 and shift selectivity of 4${\mu}{\textrm}{m}$ using the 2D random phase mask. Also, we develop a recording pattern and image processing which are suitable for a low cost reader without a position sensing photo-detector for real time data extraction and remove danger of fraud from unauthorized person by comparing the reconstructed holographic data with the live fingerprint data.

• Proceedings of the KIEE Conference
• /
• 1998.11c
• /
• pp.984-986
• /
• 1998

The volume holographic memory system suffers from the crosstalk noise. We study use of error correction coding(ECC) and angular multiplexing for digital holographic memory(DHM) system. The analog image is encoded to binary images by ECC. Binary images are stored using angular multiplexing in DHM. The retrieved binary images are decoded by ECC. The bit error-rate is measured for perspective of the DHM system.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.26 no.11
• /
• pp.1872-1879
• /
• 1989

In this paper, we implement optical holographic associative memory based on the two-dimensional neural network model by using commercial LCTV as a spatial light modulator. The system consists of the simple Vander Lugt correlator utilizing plane Fourier hologram and the pinhole array. The associated output signal is detected on a two-dimensional CCD camera and electronically thresholded and fed back to the input plane of the system. Through the experimental demonstration of nonlinear holographic associative memory, it is suggested that commercial LCTV can be used as a new coherent spatial light modurator.